Key information relevant to the recruitment process for the
overall study, such as dates of the recruitment period and locations

Participants were healthy adult males and females recruited from existing volunteer populations and from the communities at large around the clinical sites. Participants were enrolled between 7AUG2009 and 28AUG2009.

Pre-Assignment Details

Significant events and approaches for the overall study
following participant enrollment, but prior to group assignment

Explanation of how the number of participants for analysis was determined.
Includes whether analysis was per protocol, intention to treat, or another method.
Also provides relevant details such as imputation technique, as appropriate.

Number of Participants Age 18 to 64 Years With a Serum Hemagglutination Inhibition Assay (HAI) Antibody Titer of 1:40 or Greater Against the H1N1 2009 Virus 21 Days Following the First Dose of H1N1 Vaccine [ Time Frame: Day 21 after first H1N1 vaccination ]

Number of Participants Age 65 Years and Older With a Serum Hemagglutination Inhibition Assay (HAI) Antibody Titer of 1:40 or Greater Against the H1N1 2009 Virus 21 Days Following the First Dose of H1N1 Vaccine [ Time Frame: Day 21 after first H1N1 vaccination ]

Number of Participants Age 18 to 64 Years With 4-fold or Greater Hemagglutination Inhibition Assay (HAI) Antibody Titer Increases Against the Influenza H1N1 2009 Virus 21 Days Following the First Dose of H1N1 Vaccine [ Time Frame: Day 0 prior to vaccination and 21 days after the first H1N1 vaccination ]

Number of Participants Age 18 to 64 Years With 4-fold or Greater Hemagglutination Inhibition Assay (HAI) Antibody Titer Increases Against the Influenza H1N1 2009 Virus 21 Days Following the First Dose of H1N1 Vaccine

Measure Description

Blood was collected from participants for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 21 post first H1N1 vaccination titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 21 titer was an increase by 4-fold or more. Day 21 post first H1N1 vaccination is Study Day 42 for Group 4, and is Study Day 21 for all other groups.

Time Frame

Day 0 prior to vaccination and 21 days after the first H1N1 vaccination

Safety Issue

No

Population Description

Explanation of how the number of participants for analysis was determined.
Includes whether analysis was per protocol, intention to treat, or another method.
Also provides relevant details such as imputation technique, as appropriate.

Participants who received the H1N1 vaccination and from whom blood was collected at the timepoint, both within 4 days of the window, are included. Seven participants were excluded due to eligibility deviations, vaccine administration error or other protocol deviations. Analyses are as treated. This outcome restricts to age stratum.

Number of Participants Age 18 to 64 Years With 4-fold or Greater Hemagglutination Inhibition Assay (HAI) Antibody Titer Increases Against the Influenza H1N1 2009 Virus 21 Days Following the First Dose of H1N1 Vaccine
[units: Participants]

84

83

89

78

No statistical analysis provided for Number of Participants Age 18 to 64 Years With 4-fold or Greater Hemagglutination Inhibition Assay (HAI) Antibody Titer Increases Against the Influenza H1N1 2009 Virus 21 Days Following the First Dose of H1N1 Vaccine

5. Primary:

Number of Participants Age 65 Years and Older With 4-fold or Greater Hemagglutination Inhibition Assay (HAI) Antibody Titer Increases Against the Influenza H1N1 2009 Virus 21 Days Following the First Dose of H1N1 Vaccine [ Time Frame: Day 0 prior to vaccination and 21 days after the first H1N1 vaccination ]

Number of Participants Age 18 to 64 Years With 4-fold or Greater Hemagglutination Inhibition Assay (HAI) Antibody Titer Increases Against the Virus Strains in the 2009-2010 Trivalent Influenza Vaccine (TIV) 21 Days Following the Last Vaccination [ Time Frame: Day 63 ]

Number of Participants Age 65 Years and Older With 4-fold or Greater Hemagglutination Inhibition Assay (HAI) Antibody Titer Increases Against the Virus Strains in the 2009-2010 Trivalent Influenza Vaccine (TIV) 21 Days Following the Last Vaccination [ Time Frame: Day 63 ]

Number of Participants Age 18 to 64 Years With 4-fold or Greater Hemagglutination Inhibition Assay (HAI) Antibody Titer Increases Against the Influenza H1N1 2009 Virus 21 Days Following the Second Dose of H1N1 Vaccine [ Time Frame: Day 0 prior to vaccination and 21 days after the second H1N1 vaccination ]

Number of Participants Age 65 Years and Older With 4-fold or Greater Hemagglutination Inhibition Assay (HAI) Antibody Titer Increases Against the Influenza H1N1 2009 Virus 21 Days Following the Second Dose of H1N1 Vaccine [ Time Frame: Day 0 prior to vaccination and 21 days after the second H1N1 vaccination ]

Number of Participants Age 18 to 64 Years With a Serum Hemagglutination Inhibition Assay (HAI) Antibody Titer of 1:40 or Greater Against the Virus Strains in the 2009-2010 Trivalent Influenza Vaccine (TIV) 21 Days Following the Last Vaccination [ Time Frame: Day 63 ]

Number of Participants Age 65 Years and Older With a Serum Hemagglutination Inhibition Assay (HAI) Antibody Titer of 1:40 or Greater Against the Virus Strains in the 2009-2010 Trivalent Influenza Vaccine (TIV) 21 Days Following the Last Vaccination [ Time Frame: Day 63 ]

Number of Participants Age 18 to 64 Years With a Serum Hemagglutination Inhibition Assay (HAI) Antibody Titer of 1:40 or Greater Against the H1N1 2009 Virus 21 Days Following the Second Dose of H1N1 Vaccine [ Time Frame: Day 21 after second H1N1 vaccination ]

Number of Participants Age 65 Years and Older With a Serum Hemagglutination Inhibition Assay (HAI) Antibody Titer of 1:40 or Greater Against the H1N1 2009 Virus 21 Days Following the Second Dose of H1N1 Vaccine [ Time Frame: Day 21 after second H1N1 vaccination ]